Convert subtitle files between all major formats: SRT (SubRip), VTT (WebVTT), ASS/SSA (Advanced SubStation Alpha), and more. Perfect for video editing, web video, and international distribution.
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Up to 100 MB free • Outputs: SRT, VTT, ASS
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Convert your files in three simple steps — no software, no signup.
Upload your subtitle file in SRT, VTT, ASS, SSA, SUB, or other supported format. Subtitle files are typically small — under 1 MB.
Choose your target subtitle format: SRT for universal compatibility, VTT for HTML5 web video, or ASS for styled subtitles in media players.
Download your converted subtitle file. Timing is preserved precisely, and styling is adapted where possible to the target format.
Convert SRT to WebVTT (VTT) for use with the HTML5 <code><track></code> element — the only subtitle format natively supported in web browsers.
VLC, Plex, Kodi, and MPV prefer SRT or ASS subtitles. Convert your subtitles to the format your media player supports for reliable display.
YouTube accepts SRT and VTT subtitle files for video captions. Convert your ASS or SSA files to SRT before uploading to YouTube.
ASS format supports rich styling — custom fonts, colours, positions, and karaoke effects. Convert to ASS to unlock advanced subtitle display options in VLC and MPC.
Different distribution platforms and regions use different subtitle formats. Convert your subtitles for film festival submissions, broadcast delivery, and streaming platforms.
Subtitle files are processed in an isolated environment and deleted automatically within one hour.
All the formats you need, all in one place.
| Format | Description | Extension | Best Used For |
|---|---|---|---|
| SRT | SubRip Text — most universal subtitle format | .srt |
YouTube, Facebook, Vimeo, media players, DVDs |
| VTT (WEBVTT) | Web Video Text Tracks — HTML5 standard | .vtt |
HTML5 video, web players, online courses |
| ASS / SSA | Advanced SubStation Alpha — styled subtitles | .ass |
Anime fansubs, styled captions, VLC/MPC |
| SUB | MicroDVD format (frame-based timing) | .sub |
Legacy DVD players and older media |
| SBV | YouTube's native subtitle format | .sbv |
YouTube Community Contributions |
| TTML / DFXP | W3C timed text for broadcast/streaming | .ttml |
Netflix, Amazon Prime, broadcast delivery |
| LRC | Lyric file for music/karaoke players | .lrc |
Music players, karaoke applications |
<track> element. VTT supports additional features like positioning and line alignment. <track> element: <track kind="subtitles" src="subs.vtt" srclang="en"> inside your <video> tag. From everyday users to professionals — see how people rely on this tool every day.
Convert SRT to VTT to use with the HTML5 <code><track></code> element — the only format browsers natively support for in-player captions.
Convert ASS/SSA anime-style or SBV auto-caption files to SRT or VTT for manual upload to YouTube's closed caption system.
Convert VTT or exotic subtitle formats to SRT or ASS for reliable display in Plex, Kodi, VLC, and MPC-HC media players.
Convert subtitle files to TTML/DFXP format required by Netflix, Amazon Prime, and broadcast distribution pipelines for international content.
Convert song lyrics between LRC (karaoke player format) and SRT/VTT for use in different music video and karaoke applications.
Many film festivals specify subtitle format requirements for submissions. Convert your working SRT or ASS files to the required delivery format.
See how we compare to desktop software and other online converters.
| Feature |
Our Tool TransmuteBox |
Subtitle Edit | Other Online |
|---|---|---|---|
| SRT ↔ VTT conversion | |||
| ASS / SSA support | Sometimes | ||
| TTML / DFXP output | |||
| Timing preserved exactly | Sometimes | ||
| Basic styling conversion | |||
| No install required | |||
| Files auto-deleted after 2 h | Varies |
Built on industry-standard open-source tools for maximum quality and reliability.
Subtitle files are deceptively simple text files — but the variety of formats reflects decades of different software ecosystems, distribution requirements, and technical needs. Knowing which format to use for your specific platform or workflow saves significant frustration.
SRT (SubRip Text) is the most widely supported subtitle format across all platforms and software. Its structure is simple:
1\n00:00:05,000 --> 00:00:08,000\nHello, world!\n\n2\n00:00:09,000 --> 00:00:12,500\nThis is a subtitle line.SRT supports basic formatting via HTML-like tags: <b>, <i>, <u>, and <font color="#ffffff">. Timing uses commas (,) as the decimal separator — not periods.
WebVTT (VTT) is the W3C standard for in-browser subtitle display. It's the only subtitle format natively supported by HTML5's <track> element. VTT is structurally similar to SRT but uses periods as decimal separators and adds support for:
::cue pseudo-element.ASS (Advanced SubStation Alpha) is the richest subtitle format, supporting:
ASS is the format of choice for anime fansubs and styled subtitle workflows in VLC, mpv, and MPC-HC.
TTML (Timed Text Markup Language) and its profile DFXP (Distribution Format Exchange Profile) are W3C XML-based subtitle formats used in professional broadcast and streaming distribution. Netflix, Amazon Prime, Hulu, and many national broadcasters require TTML for subtitle delivery.
TTML is more complex than SRT but supports full styling and positioning — and critically, it's required for closed caption compliance submissions in many markets.
<track kind="subtitles" src="video.vtt" srclang="en">.